#include "gd.h"
#include "gdhelpers.h"
#include "gd_intern.h"

/* bring the palette colors in im2 to be closer to im1
 *
 */
int gdImageColorMatch (gdImagePtr im1, gdImagePtr im2)
{
  unsigned long *buf; /* stores our calculations */
  unsigned long *bp; /* buf ptr */
  int color, rgb;
  int x,y;
  int count;

  if( !im1->trueColor ) {
    return -1; /* im1 must be True Color */
  }
  if( im2->trueColor ) {
    return -2; /* im2 must be indexed */
  }
  if( (im1->sx != im2->sx) || (im1->sy != im2->sy) ) {
    return -3; /* the images are meant to be the same dimensions */
  }
  if (im2->colorsTotal<1) {
    return -4; /* At least 1 color must be allocated */
  }

  buf = (unsigned long *)safe_emalloc(sizeof(unsigned long), 5 * im2->colorsTotal, 0);
  memset( buf, 0, sizeof(unsigned long) * 5 * im2->colorsTotal );

  for (x=0; x<im1->sx; x++) {
    for( y=0; y<im1->sy; y++ ) {
      color = im2->pixels[y][x];
      rgb = im1->tpixels[y][x];
      bp = buf + (color * 5);
      (*(bp++))++;
      *(bp++) += gdTrueColorGetRed(rgb);
      *(bp++) += gdTrueColorGetGreen(rgb);
      *(bp++) += gdTrueColorGetBlue(rgb);
      *(bp++) += gdTrueColorGetAlpha(rgb);
    }
  }
  bp = buf;
  for (color=0; color<im2->colorsTotal; color++) {
    count = *(bp++);
    if( count > 0 ) {
      im2->red[color]   = *(bp++) / count;
      im2->green[color] = *(bp++) / count;
      im2->blue[color]  = *(bp++) / count;
      im2->alpha[color] = *(bp++) / count;
    } else {
      bp += 4;
    }
  }
  gdFree(buf);
  return 0;
}


